tools/hv: Fix file handle leak

commit d5ab482799e7c4c4b7c0aa67e8710dce28115d03 upstream.

Match up each fopen() with an fclose().

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>